Conventional hydrogen (H2) gas sensors suffer from poor sensitivity due to the lack of selectivity in their sensing mechanism. Specifically, hydrogen sensors are prone to contamination from carbon monoxide, carbon dioxide, and acetylene, as well as other hydro-carbons, all of which can contribute to an erroneous estimation of the concentration of hydrogen gas in a sample.
In a measurement setting, this cross-contamination can be characterized by a shift from an H2baseline. Furthermore, in addition to the presence of these contaminants, variations within the sensing layer structure of the sensor as well as the different spatial thermal gradients that arise in the sample prior to measurement also contribute to the shift from the H2baseline, thereby yielding an incorrect estimation of the hydrogen content. These issues, whether taken alone or together, all contribute in raising the detection limit of current hydrogen sensors.